#include <stdio.h>

int
main ()
{
	double curr, next, prev;

	scanf("%lf", &prev);
	printf("%lf ", prev);
	if (scanf("%lf", &curr) == 1) {
		next = curr;
		while (scanf("%lf", &next) == 1) {
			printf("%lf ", (prev+next)/2);
			prev = curr;
			curr = next;
		}
		printf("%lf\n", next);
	}
	return 0;
}